1. Field of Invention
The present invention concerns the jet spray dispersal of fluid from a nozzle structure for purposes such as irrigation or fire fighting when water or fire suppressant chemicals are used as the fluid medium. However, the invention also has application in such diverse areas as hydraulic excavation, combustion and deflagration initiation from a distance or in other areas of technology where changes of state or chemical reactions in the sprayed fluids are beneficial to the purpose of the application. Examples of these applications will be brought forward in the detailed description to illustrate the versatility of the invention.
2. Description of the Prior Art
Jet sprays produced by nozzles or orifices are well known in irrigation and fire fighting technology. These jet sprays are ejected from single nozzles. A plurality of nozzles or orifices may be used, sometimes on near parallel axes to give intermediate and close-in water coverage in conjunction with longer trajectory jet patterns. But single jet sprays have a common problem. They interact with the surrounding air to produce free turbulence, especially at the outer perimeter of the jet. This turbulence successively strips liquid from the outer layer of the jet pattern causing loss of mass from the main jet and otherwise adversely affecting the jet. This circumstance is not intolerable in irrigation applications where jet spray is intended to drop out along the trajectory. Nevertheless, the jet nozzle configuration must usually be designed for a given range and water drop out as a function of distance from the nozzle for some limited range of water pressure. If the pressure lies outside this design range, the nozzle performance deteriorates significantly.
Deterioration by free turbulence of a jet spray in firefighting is undesirable; because, by the nature of this application, the spraying equipment must stand off from the target. Liquid loss between the nozzle and the target reduces efficiency.